The invention relates to a filter candle for a pressure filter for liquids in a pressure container.
Pressure filter elements of this kind are known in German Offenlegungsschrift No. 2,741,639, in which a plurality of depending filter elements are arranged in a pressure container and are covered with filter tissues.
The removal of filter cakes does not provide any difficulties in such filter elements, as long as the cake to be removed is in a relatively moist state. Problems do, however, occur when the filter cake should be discharged in a dry form. During the filtration, for example of lime, a filter cake continuously extending from the top to the bottom of 2-3 cm thickness is obtained on the filter surface of a, for example, 200 cm long and 8 cm thick filter element which is covered with a respective filter tissue. Upon backwashing with air, the cake is dropped in form of 20-50 cm long pieces. During the dry discharge of the filter cake, these pieces can jam with each other between adjacent filter elements and consequently do not drop to the bottom of the container, thereby obstructing the discharge. This is especially true when long filter candles are concerned, which generate large and long filter cake pieces.